Safety-valve.



2. 0. w. 9.1 m .o n d .n n 6 t .a P T E. .TV Em. WV Uv... Pn .A uns 7. o7, w 7 o. N

(Application filed Apr. 5, 1902.)

'2 sham-sheet (un Mom.)

mlm

UNITED STATES PATENT OFFICE.

HAROLD P. TIPPETT, OF COLUMBUS, OHIO. I

SAFETY-VALVE.

SPECIFICATION forming part of Letters Patent No. 715,707, dated December9, 1902.

Application tiled April 5, 1902. Serial No. 101,518. (No model.)

To all whom it may concern.:

Be it known that I, HAROLD P. TIPPETT, a citizen of the United States,residing at Columbus, in the county of Franklin and State of Ohio, haveinvented certain new and useful Improvements in Safety-Valves, of whichthe following is a specication.

This invention relates to steam engine valves, and particularly to asafety-valve for locomotive and other boilers.

The invention embodies various improvements in safety-valves, andespecially in the safety-valve covered by Letters Patent issued to meMay 11, 1897, numbered 582,445, and in the valve covered by myapplication led March 18, 1902, ySerial No. 97,320.

The first or principal object of this invention is to provide in asafety-valve a construction and arrangement of parts to effect theclosing or seating of -a vertically slidable main valve in the directionof the ow of steam from a boiler instead of against such steam Iiow, ascovered by the above-mentioned patent.

Afurther purpose of the invention is to provide in a safety-valve avertically-slidable main valve having a central opening around which isformed a valve-seat, the bottom of the main valve being solid or closed,except for said opening, and Without a port or ports, as shown in mypatent hereinbcfore referred to. In said patent the main valve has anopen top and is cup-shaped, so that the bottom is of smaller area thanthe top; but in this application I provide the main valve with a sleevehaving a piston of larger area than the said valve.

In the accompanying drawings,` forming part of this application, Figurel is a perspective view, partly broken away, of a valve constructedunder this application. Fig.'2 is a central vertical section withoutmuftiers. Fig. 3 is a cross-section on the plane indicated by the lineFig.2. Fig. 4is a perspective view of the main valve. Fig. 5 is 'acentral vertical section of a modification. Fig. 6 is a section ofmodified form of main valve.

The same numeral references denote the same parts throughout the severalviews of the drawings.

The valve-body consists of an outer casing 1, adapted to be attached toa locomotive or other steam boiler, and having valve-guides 2, and avalve-seat 3; an inner shell 4, having a central valve-sleeve, bearing5, and joined to the casing bya series of ribs 6, which form with thecasing and shell, a series of exhaustports 7.

The main valve comprises a hollow sleeve 8, working steam-tight in thebearing 5 and opening through an otherwise closed 0r solid bottom 9,which works between the guides 2 and has a valve-seat 10 formed upon itsupper surface to coperate with the vseat 3 and a piston 11, secured tothe top of the stem 8 and making a steam-tight bearing against the shell4. The shell 4 is provided with a cover 12, having a hollow dependingstem 13, over which the sleeve is fitted steam-tight. The stem 13 isprovided with a valve-seat 14, and adjacent to the latter are ports 15through the stem. The cover I12 has one or more ports 1G anda head 17 toreceive a nut 18, having inside and outside screw-threads. A hood 19-isscrewed to the top of the nut 18 and holds the outer muffler 20 and theinner conical muffler 21 to the nut and in position on the valve-casing.

The controlling-valve 22 has an open top and a closed bottom and isprovided With a valve-seat 23 to engage the valve-seat 14. From the seat23 to the top of the valve 22 the latter makes a steamtight joint withthe cover l2 and the stem 13, and from the said seat 23 thecontrolling-valve 22 is reduced to the bottom thereof to leave alive-steam passage between the controlling-valve and the stem 13.

The means for regulating the spring 24 and adjusting'the valve 22 isdisclosed in my application hereinbefore referred to, but not thereinclaimed specifically. It consists of a hollow bolt 25, held to the nut18 by a nut 26, a rod 27, having a shoulder 28 to engage the spring, anda set-bolt 29 to Work the rod 27 in the hollow bolt 25. The hood 19covers this mechanism and protects it from accidental movement.

Referring to the modification shown in Fig. 5 of the drawings, thevalve-casingis the same as that before described herein, except it is.without valve-guides and has an external thread 30 for attaching themuftlers 31 and 32 instead of attaching them as already de IOO scribed.Thecover33 hasnodependingstem; but a central flange 34 is formed on thetop of the cover, through which a stem 35 of the main-valve piston 36works, so as to leave an exhaust-passage 37. The said stem has ports 38adjacent to a valve-seat 39 formed on the cap 36, and the stem 35 has aninternal thread by which the nut 40 is attached and is free to be movedunder the action of the main valve vertically through the mulilers. Aspring 41 may be employed to hold the main valve seated when there is nopressure on a boiler. In the construction shown in Fig. 5 the main valveand all of its connections are slidable vertically through the shell andshell-cover, so that when the main valve lifts all of its parts arelifted with it, and the controllingvalve is also lifted within and bythe main valve.

Fig. 6 shows a stem 42 integral with the top of the main valve andscrewed into a iange 44 of the bottom 45 of said valve.

The operation of the preferred form of valve is as follows: Steam fromthe boiler inducts against the bottom of the main valve and holds ittoits seat, while the same steampressure raises the controlling-valveand permits such steam to pass from around the controlling-valve throughthe stem-ports and eX- erts itself upon the top of the main piston, andthe latter being of greater area than the bottom of the main valve thelatter is forced open or downwardly unseated, which permits the exhaustto be made through the ports of the valve-casing. When theboiler-pressure is reduced sufficient to seat the controllingvalve, thesteam above the main Valve discharges through the port or ports inthecasing-cover, and the main valve is again seated by the boiler-pressure.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

l. In a safety-valve, the main valve having a sleeve making asteam-tight bearing on the body of the safety-valve and open at eachend, a piston on the sleeve of greater area than the main valve, andmeans for admitting steam-pressure above the piston.

2. In a safety-valve, a projecting stern provided with a Valve seat andports, a controlling-valve operated by steam in the stem to open andclose the said ports, and a main valve having a piston of larger areathan the valve.

3. In a safety-valve, a stern depending from the valve-cover and havinga seat and ports,

a controlling-Valve slidable in the stem to open and close the saidports, and a main valve having a sleeve slidable on the stem andconnecting the piston and Valve of the main Valve.

4. In a safety-valve, a valve-cover having steam-exits, a stem dependingfrom the cover and provided with a valve-seat, and ports, acontrolling-valve slidable in the stem to open and `close the ports, amain valve having a piston of greater area than the valve, and a sleeveconnecting the piston to the valve, and slidable on said stem.

5. In a safety-valve, a stem having ports projecting from the coverthereof, a safetyvalve proper having a sleeve open at each end andWorking on the stem, a piston on the sleeve of larger area than thevalve, and means for admitting steam-pressure above the piston.

6. In a safety-valve, a stem having ports and projecting through andfrom the cover thereof, a safety-valve proper having a sleeve open ateach end, and a piston on the sleeve of larger area than the valve,combined with a controlling-valve Working in the stem.

7. In a safety-valve, the combination of the casing having a valve-seat,a piston, valveguides depending from the seat, a shell supported in thecasing so as to form ports between the casingand the shell, and meansfor admitting steam-pressure above the piston.

8. In a safety-valve, the combination, with the casing having avalve-seat, the shell having a central bearing, and the casing-coverhaving a depending stem provided with a seat and ports, of aspring-controlled valve slidable in the stem so as to leave asteam-passage around the valve to said ports, and a main valve workingin said bearing and having a removable piston of larger area than themain valve, and a sleeve forming the only opening in the main valve andconnecting the piston therewith.

9. The combination, with the shell and casing, of a main valve having apiston of larger area than the valve, a stem provided with ports and avalve-seat and projecting from the piston slidably through the top ofthe shell, and a controlling-valve operated in the stem to open andclose said ports.

In witness whereof I hereunto set my hand in the presence of twowitnesses.

' HAROLD P. TIPPETT.

l/Vitnesses: l

CHARLES S. M. TRUMAN, NORMAN L. I-IAYDEN.

